Twelve-year old Anna has asthma. She lives in a low-income neighborhood and gets her care at a clinic affiliated with a major teaching hospital. Despite high-quality medical care, Anna’s asthma is not well controlled. Last year she missed almost two weeks of school, had two urgent care visits, and a brief but scary (and expensive) hospital stay. Her pediatrician believes that the old, rent-subsidized apartment where Anna’s family lives may be part of the problem: The presence of mold, moisture, rodents, and dust mites, for example, may trigger her asthma attacks but lie beyond the scope of a clinical intervention.

Situations like Anna’s (a composite illustration) are a major factor in worsening health and rising health care costs in the United States. Unhealthy living conditions, nutrition, and a host of social and environmental factors turn potentially manageable health issues into costly ones for both patient and provider. Indeed, the Robert Wood Johnson Foundation, the largest private US grantmaker focused on health, estimates that just 20 percent of a person’s health is related to health care. The rest stems from behavioral, environmental, and social factors. As highlighted by The Commonwealth Fund, asthma symptoms can be linked to where families live; frequent emergency-department visits and hospitalizations can be linked to homelessness; and diabetes-related hospital admissions and other health problems can be linked to food insecurity. In health systems like Kaiser Permanente—one of the largest managed care organizations in the United States—just one percent of the patient population accounts for approximately 25 percent of the total cost of medical services provided annually, often due to non-medical factors.